<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>04_粘性定位</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        body {
            height: 2000px;
        }
        .page-header {
            height: 100px;
            text-align: center;
            line-height: 100px;
            background-color: orange;
            font-size: 20px;
        }
        /* .content { */
            /* height: 200px; */
            /* overflow: auto; */
            /* overflow: scroll; */
        /* } */
        .item {
            background-color: gray;
        }
        .first {
            background-color: skyblue;
            font-size: 40px;
            position: sticky;
            top: 0px;
            /* float: right; */
            /* margin-right: 100px; */
        }
    </style>
</head>
<body>
    <!-- 头部 -->
    <div class="page-header">头部</div>
    <!-- 内容区 -->
    <div class="content">
        <!-- 每一项 -->
        <div class="item">
            <div class="first">A</div>
            <h2>A1</h2>
            <h2>A2</h2>
            <h2>A3</h2>
            <h2>A4</h2>
            <h2>A5</h2>
            <h2>A6</h2>
            <h2>A7</h2>
            <h2>A8</h2>
        </div>
        <div class="item">
            <div class="first">B</div>
            <h2>B1</h2>
            <h2>B2</h2>
            <h2>B3</h2>
            <h2>B4</h2>
            <h2>B5</h2>
            <h2>B6</h2>
            <h2>B7</h2>
            <h2>B8</h2>
        </div>
        <div class="item">
            <div class="first">C</div>
            <h2>C1</h2>
            <h2>C2</h2>
            <h2>C3</h2>
            <h2>C4</h2>
            <h2>C5</h2>
            <h2>C6</h2>
            <h2>C7</h2>
            <h2>C8</h2>
        </div>
    </div>
</body>
</html>